The present invention refers to an adapter for fastening snow chains to vehicle wheels.
A type of snow chain is currently know on the market comprising various sections of chain closed in a loop and disposed on the tread of the tire of the vehicle wheel. The sections of chain are connected to arms or spokes disposed radially on the outside of the wheel and ending in a box or disc-shaped plate designed to be disposed substantially coaxially to the wheel hub. The disc-shaped plate is fixed to the wheel by means of an adapter device which grips the head of at least one of the wheel mounting bolts.
Adapter devices are known on the market in the form of a cylindrical sleeve provided with an operating ring nut, rotation whereof operates the teeth for tightening to the head of the wheel bolt. Said operating ring nut is disposed on the outside of the sleeve to be able to be operated in rotation by the user, possibly with the aid of a special key, such as for example the hexagonal key used for fitting/removing the wheels of the vehicle.
The adapter device can have a transverse hole to receive a bar connected to the disc-shaped plate of the arms of the snow chains, or other fastening devices, such as a transverse lever with an end hold, which is disposed more or less in the centre of the rim.
Other types of adapter devices are known which comprise a disc-shaped late provided with mechanical clamping devices which grip all the bolts of a wheel.
It is obvious that the adapter devices according to the prior art have drawbacks due to the complexity of their installation and removal. In fact the installation and removal operation of the adapter devices proves awkward, long, troublesome and sometimes requires the use of special tools.